Stretchable substrates that have an elastomeric net and a non-woven fabric bonded thereto are known (Patent Documents 1, 2). Patent Document 1 discloses a technique for manufacturing a stretchable substrate by laminating a stretchable meshed material, which consists of continuous linear members made of styrene-based elastomer, on one of the surfaces of a non-woven fabric. Patent Document 2 discloses a technique for manufacturing a stretchable substrate by laminating a non-woven fabric, which is made of staples and which have been subjected to carding, on one or both sides of an elastomeric net and by intertwining the net and the fabric by means of water jet (high pressure liquid flow treatment).
However, the non-woven fabric in the stretchable substrate fabricated by these techniques is stretchable in any direction because the fibers forming the non-woven fabric are curved and randomly oriented. As a result, the stretchable substrate having the non-woven fabric and an elastic meshed material (a net) laminated thereon is also stretchable in any direction.
On the other hand, stretchable substrates may be required to be stretchable only in one direction with limited stretchability in the orthogonal direction for use in specific applications, such as the substrate of masks and supporters etc. Furthermore, when a stretchable substrate is bonded to another material while they are fed from individual feed rolls in order to manufacture a final product, large stretchability of the stretchable substrate may limit the feed speed of the feed rolls. Therefore, there is also a need of limiting the stretchability for the purpose of increasing the feed speed and improving production efficiency.
Under such circumstances, a technique has been developed in which lateral strands of a net are formed of stretchable elastomer while longitudinal strands thereof are formed of a non-elastomeric material having limited stretchability. Such a net exhibits conventional stretchability in the direction along the lateral strands and limited stretchability in the direction along the longitudinal strands. One of the examples is “REBOUND”, a net manufactured by CONWED PLASTICS, LLC, USA (Patent Document 3). This net has lateral strands formed of styrene-based block copolymer and longitudinal strands formed of polypropylene (PP), and intersections of the lateral and longitudinal strands are thermally fused.